Sorry in advance for this long post. I have owner my 2001 Z06 for about a year now. This is a great car and has been a pleasure to own and drive----with one exception. It appears that every time I wash the car, I get moisture somewhere that causes my car to show a "Door Ajar" alarm and the interior lights stay on until I open and close the passenger door. To make matters worse, if I try to lock my car while it is doing this-----hello flashing lights and alarm!!!!! I took it to the dealership a few months ago while it was doing this-----I had as much idea of what was going on as they did. They told me that the BCM was going bad and that since it happened when I washed the car, that it may have gotten moisture in the BCM. Well, the worst thing that I ever did was tell them that it happened when I washed the car-------the extended warranty does not cover anything to do with moisture or water (according to the guy I argued with that had an accent that did not sound like he was from the Chevrolet Headquarters, unless the Chevrolet Headquarters has moved to India). Anyway, the dealership concluded that the seal strips in the doors were causing moisture to get into some sensors and the Warranty guy stated that this would not be covered because it was due to moisture. I decided to at least show some initiative and bought the door seal strips and had them installed by another dealership. I knew this was not going to fix the problem, but the strips had cracked where someone had overtightened the screws, so they needed replacing anyway. $378 later, I contacted Chevrolet and told them what happened with the Warranty and they graciously told me to send them the bill and they would take care of it. I sent it in and they actually sent me a check to cover the amount.

My car has done this crazy alarming since that time and I have usually been able to let it sit overnight after washing it and it seems to fix itself----until yesterday. I got home from cleaning the car, locked the door, walked upstairs and fifteen minutes later the alarm starts doing its job. I hit the alarm button on the remote and it goes off, but the interior lights stay on inside the car (not good for the battery). If I open the passenger side door and close it, the interior lights go off and all is good unless I arm the alarm again (then the alarm starts alarming), or start the car and kill it (then the interior lights stay on until I open and shut the passenger door. The only "safe" bet is to leave the car unlocked and open and close the passenger door every time I use the car.

I took the car by another dealership today and to my dismay they had no idea (they didn't even look at the car) and they told me that the earliest they could get it in to work on it would be the middle of next week. Needless to say, i am not too enthused with their lack of help.

It really sounds to me like a door sensor is getting moisture in it. Has anyone got any insight into this phenomenon?

 

Nope. But, it is time for some isolationism.
A spray bottle and some of your time is going to be required here.
Or the opposite, secure any spot (or area) that you believe it to be and wash the car to re-create the problem. If the problem does not happen, on the next wash, do not cover all that you covered. May take a couple of washes, but you gotta prove "what it's not."
You can do this. Whip out your lab coat and become a scientist for a day.

 

I don't mind the work, but I thought someone else may have expereienced the same problem and could give me an idea on what caused their problem. It looks like I found 2 others on the board who had the exact same problem. I e-mailed them. Hopefully, they can give me an insight into a fix. Again, thanks. I will keep everyone updated.

 

If BCM you can read codes that are displayed. BCM failure will cause additional problems then you have experienced.

 

there is a panel right front behind tire,jack your car up take tire off you will see the panel remove the seven screws remove you will see water in there clean water out,pull apart(8 mm bolt)on computer,also clean relay off with low air presuretry delectric grease and cleaner there is also 2 ground not leasted by GM